I have a problem in finding friction (Theoretically). Actually i am trying to develop an Equation for Friction. I have a Plunger and a guidance of both 5.5mm. With Plunger having g6 tolerance and Guidance with H7 tolerance. Consider that input force is from 1N-10N and the Plunger causes a To & Fro motion. Pls help me in finding the friction equation for this.